Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/42—Stripping or agents therefor
  • G03F7/422—Stripping or agents therefor using liquids only
  • G03F7/425—Stripping or agents therefor using liquids only containing mineral alkaline compounds; containing organic basic compounds, e.g. quaternary ammonium compounds; containing heterocyclic basic compounds containing nitrogen

Definitions

• This invention relates to novel resist stripping compositions and to methods of stripping resists employing said stripping compositions. More particularly, this invention relates to a novel resist stripping composition comprising a mixture of a pyrrolidinone compound and a diethylene glycol monoalkyl ether compound and which can also include polyethylene glycol and to stripping resists with said stripping compositions.
• Modern technology utilizes positive-type resist materials for lithographically delineating patterns onto a substrate so that the patterns can be subsequently etched or otherwise defined into the substrate material.
• the resist material is deposited as a film and the desired pattern is defined by exposing the resist film to energetic radiation. Thereafter the exposed regions are subject to a dissolution by a suitable developer liquid. After the pattern has been thus defined in the substrate the resist material must be completely removed from the substrate to avoid adversely affecting or hindering subsequent operations or processing steps.
• the resist materials have been removed by stripping agents containing one or more of the following: halogenated hydrocarbons, for example, methylene chloride or tetrachloroethylene; amines and their derivatives such as dimethylformamide, N-methyl-2-pyrrolidone, diethanolamine and triethanolamine; glycol ethers such as ethylene glycol monoethyl ether, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, and the acetates thereof; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone, as well as such materials as dioxane, sodium phenolate, isopropyl alcohol, sulfuric acid/nitric acid mixtures, persulfuric acid mixtures such as Caro's acid and sulfuric acid ammonium persulfate, and mixtures of caustic and phenol derivatives as well as various other materials.
• halogenated hydrocarbons for example,
• each such stripping agent there may be mentioned the following: undesirable flammability, volatility, odor and toxicity; incomplete removal of all resist film; effectiveness only on certain resist films; attack of components other than the resist material, such as attack of the metal substrates by the stripping agent; safety in handling and disposal of the stripper; and the undesired necessity for use at specified elevated temperatures when selected resists are being stripped.
• the limited stripping capabilities of the stripping agents is a very decided drawback. Additionally many such strippers are not sufficiently effective against resist materials that are subject to a severe post-baking operation thereby limiting their usefulness. In some of the strippers the presence of water is extremely detrimental. Additionally, for those stripping applications requiring inertness of the agent to metal substrates, toxicity during handling and difficulty of disposal are primary drawbacks.
• novel stripping compositions also exhibit a synergistically enhanced stripping action and provide resist stripping capabilities not possible from the use of the individual components used alone as photoresist strippers.
• novel stripping compositions of this invention comprise a mixture of from about 55 to about 80 percent by weight of a 2-pyrrolidinone compound and from about 20 to about 45 percent by weight of a diethylene glycol monoalkyl ether compound.
• stripping compositions are provided if there is added to the basic misture from about 3 to about 30 percent by weight of polyethylene glycol.
• the presence of water in the stripping compositions of this invention is not detrimental and can be present in an amount of from about 0 to about 10 percent by weight without undue adverse effects resulting.
• the invention also relates to the use of such stripping compositions for removing photoresist material from a substrate surface.
• stripping compositions of this invention comprise stripping compositions containing from about 55 to about 80 weight percent, preferably from about 60 to about 75 weight percent, and most preferably about 73 weight percent a 2-pyrrolidinone compound of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms and hydroxyalkyl of 1 to 3 carbon atoms, and from about 20 to about 45 weight percent, preferably about 25 to about 40 weight percent, and most preferably about 27 weight percent of a diethylene glycol monoalkyl ether of the formula
• R 1 is alkyl of 1 to 4 carbon atoms.
• 2-pyrrolidinone compounds suitable for use in this invention there may be mentioned, for example, 2-pyrrolidinone, 1-methyl-2-pyrrolidinone, 1-ethyl-2-pyrrolidinone, 1-propyl-2-pyrrolidinone, 1-hydroxymethyl-2-pyrrolidinone, 1-hydroxyethyl-2-pyrrolidinone, and 1-hydroxypropyl-2-pyrrolidinone.
• 2-pyrrolidinone 1-methyl-2-pyrrolidinone
• 1-ethyl-2-pyrrolidinone 1-propyl-2-pyrrolidinone
• 1-hydroxymethyl-2-pyrrolidinone 1-hydroxyethyl-2-pyrrolidinone
• 2-hydroxypropyl-2-pyrrolidinone 2-pyrrolidinone
• 2-pyrrolidinone 1-methyl-2-pyrrolidinone
• 1-ethyl-2-pyrrolidinone 1-propyl-2-pyrrolidinone
• 1-hydroxymethyl-2-pyrrolidinone 1-hydroxyethyl-2-pyrroli
• diethylene glycol monoalkyl ether compounds suitable for use in this invention there may be mentioned, for example, 2-(methoxyethoxy)ethanol, 2-(ethoxyethoxy)ethanol, 2-(2-propoxyethoxy)ethanol and 2-(butoxyethoxy)ethanol.
• 2-(2-ethoxyethoxy)ethanol is especially preferred.
• An even more effective and desirable stripping composition is provided when from about 3 to about 30 weight percent, preferably about 5 to about 25 weight percent, and most preferably about 6 to about 15 weight percent polyethylene glycol is added to the aforementioned stripping mixture.
• a most preferred stripping composition of this invention comprises a mixture of from about 50% 1-methyl-2-pyrrolidinone, about 25% 2-(2-ethoxyethoxy)ethanol and about 25% polyethylene glycol.
• compositions of this invention can be free of water this is not essential and water can be present in an amount of up to about 10 percent by weight.
• compositions of this invention there can be mentioned the following compositions of Table I.
• any suitable polyethylene glycol may be employed although polyethylene glycol of a molecular weight of about 200 is preferred.
• the stripping compositions of this invention are effective in stripping a wide and varied range of positive photoresists.
• Most positive photoresists consist of an ortho napthoquinone diazide sulfonic acid ester or amide sensitizer or photoactive component, with novolak, resole, polyacrylamide or acrylic copolymer type binders or resins.
• Such positive photoresists are well known in the art.
• resists and sensitizers are described, for example, in U.S. Pat. Nos. 3,046,118; 3,046,121; 3,106,465; 3,201,239; 3,538,137; 3,666,473; 3,934,057; 3,984,582 and 4,007,047.
• positive photoresist compositions for which the stripping compositions of this invention may be used there may be mentioned Eastman Kodak Company photoresist Kodak 809; J. T. Baker Chemical Company photoresist PR-20; Philip A. Hunt Chemical Corp. Waycoat HPR 104, HPR 106, HPR 204 and HPR 206 photoresists; Shipley Company Inc. photoresists AZ-1350, AZ-1350B, AZ-1350H, AZ-1350J, AZ-1370, AZ-1450B, AZ-1450J, AZ-1470, AZ-2400 and AZ-111; Polychrome Corporation photoresists PC-129, PC-129SF and PC-138; Fuji Chemicals Industrial Co. photoresist FFPR-200; and Tokyo Ohka Kogyo Co. Ltd. photoresist OFPR-800.
• the stripping compositions of this invention are effective in removing photoresist materials from substrates even when they have been subjected to a post-bake treatment at about 150° C. for a period of about one hour.
• the stripping compositions of this invention are especially advantageous for numerous reasons among which may be mentioned the following.
• the stripping compositions remove positive photoresist materials from metal and other substrates without attacking the substrate.
• the compositions are essentially non-toxic and are water miscible. The presence of water during the stripping operation is not deleterious to the operation of the stripping composition.
• phenolic based strippers the compositions of this invention require no special handling and are easily disposed of in normal sewage treatment facilities.
• the bath life and stripping effectiveness of the compositions are for the most part independent of temperature.
• Use of the stripping compositions of this invention requires only a subsequent rinse with deionized water whereas many prior strippers require the use of additional organic solvents.
• stripping compositions of this invention completely remove difficult-to-remove positive photoresists at about 75° C. or less whereas some prior art strippers require both temperatures of about 95° to 100° C. Also, most positive photoresists are completely stripped in about one minute or less while stripping times of 5 to 20 minutes are recommended for many commercial stripping compositions.
• 1-methyl-2-pyrrolidinone itself has been suggested as a stripping agent for certain positive photoresists, said compound is not an effective stripper for various positive photoresists. It has been unexpectedly found that the stripping compositions of this invention effectively and completely remove positive photoresist material from substrates which photoresist materials are not effectively and completely removed by the individual components of the compositions of this invention. The effectiveness and unexpected nature of the stripping action of stripping composition of this invention is illustrated by the data presented in the following Table II.
• Wafer substrates were coated with positive photoresist materials according to art recognized procedures and post-baked at about 150° C. for a period of about 45 minutes to one hour. Stripping baths were maintained at constant temperature with water baths and the post-baked coated wafers were immersed into 600 ml beakers containing the constant temperature stripping compositions with intermittent agitation for the specified times after which the wafer is removed, rinsed in running deionized water and spin dried at 3000 rpm. Strippability was judged by inspection of the wafers to ascertain if any residue was present.
• Compositions of this invention are compared to results obtained for the individual components alone for three generally difficult-to-remove photoresists namely Shipley's AZ-1350J photoresist, Tokyo Ohka Kogyo Co. Ltd.'s OFPR-800 photoresist and Fuji's FPPR-200 photoresist.
• stripping compositions of this invention can be used as stripping agents for positive photoresists by contacting the unexposed photoresist on a substrate with the stripping compositions in a variety of means, such as by immersion in a stripping bath or by spraying the stripping composition over the surface of the unexposed photoresist.
• stripping compositions of the invention are suitable for other uses which will be apparent to those skilled in the art, such as, for example, in the stripping of polymer residues from reaction or curing vessels and the like, or for stripping coatings, such as, for example, paints and varnishes and the like, from surfaces.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
• Detergent Compositions (AREA)
• Hydrogenated Pyridines (AREA)
• Developing Agents For Electrophotography (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Cleaning Or Drying Semiconductors (AREA)

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Cited By (47)

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Citations (6)

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• 1982
  • 1982-08-17 US US06/408,052 patent/US4428871A/en not_active Expired - Lifetime
  • 1982-08-27 IE IE2090/82A patent/IE53779B1/en not_active IP Right Cessation
  • 1982-08-31 NZ NZ201772A patent/NZ201772A/en unknown
  • 1982-09-07 IL IL66738A patent/IL66738A/xx not_active IP Right Cessation
  • 1982-09-10 AU AU88195/82A patent/AU557497B2/en not_active Ceased
  • 1982-09-18 KR KR8204228A patent/KR880002247B1/ko active
  • 1982-09-22 DK DK421982A patent/DK163841C/da not_active IP Right Cessation
  • 1982-09-22 DE DE8282108781T patent/DE3277244D1/de not_active Expired
  • 1982-09-22 EP EP82108781A patent/EP0075329B1/en not_active Expired
  • 1982-09-22 NO NO823205A patent/NO162219C/no unknown
• 1988
  • 1988-03-08 SG SG169/88A patent/SG16988G/en unknown
  • 1988-05-02 HK HK338/88A patent/HK33888A/xx not_active IP Right Cessation

Patent Citations (6)

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